Isaac Newton and Edmond Halley saving Galileo from being burnt at the stake. Topped off with the line "It's Science, punk!".
When the world of IW ended and all of the arcs combined.
Following the Total Event Collapse, Adam and Jamie try to reboot the universe with a Big Bang 2 by using the TARDIS to detonate all explosives from the entire universeever. That's right, Irregular Webcomic did it first.